(1) Field of the Invention
Photography, particularly photography of objects so as to create modified slide transparencies for use in angular (oblique) projection upon a viewing screen. Such angular projection results both in geometric distortion, known as the "Keystone effect", and in non-uniform illumination of the image upon the viewing screen. The non-uniform illumination is incident to the angle of projection, the farther portion of the image from the projection lens receiving less light and the nearer portion receiving greater light. Because of such drawbacks, projection at angles which greatly differ from normal have since been avoided.
(2) Description of the Prior Art
Being submitted separately under the provisions of 37 CFR 1.97.